Two-Dimensional Adiabatic Model for Calculating Progressions Resulting from Stretch-Rock Coupling in Vibrational Spectra of Anion-Water Complexes.

Several anion-water dimers feature a distinct progression in the OH stretch region of their vibrational spectra. This progression arises from strong anharmonic couplings between the OH stretch and low-frequency intermolecular modes. In this work, we introduce a two-dimensional adiabatic model accounting explicitly for the water and anion rock degrees of freedom and use it to calculate the vibrational spectra of HCO·(HO) and NO·(HO).

Mapping the temperature-dependent and network site-specific onset of spectral diffusion at the surface of a water cluster cage.

We explore the kinetic processes that sustain equilibrium in a microscopic, finite system. This is accomplished by monitoring the spontaneous, time-dependent frequency evolution (the frequency autocorrelation) of a single OH oscillator, embedded in a water cluster held in a temperature-controlled ion trap. The measurements are carried out by applying two-color, infrared-infrared photodissociation mass spectrometry to the DO·(HDO)(DO) isotopologue of the "magic number" protonated water cluster, H·(HO) The OH group can occupy any one of the five spectroscopically distinct sites in the distorted pentagonal dodecahedron cage structure.